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Tankless Water Heater in Austin, TX

A tankless water heater in Austin heats water as it flows, so there is no tank to run dry. The right choice depends on your gas supply, your fixtures and your water. Call any hour to talk it through.

Emergency? Call now, 24/7(737) 717-0737
Cutaway of a home showing the plumbing systemWater main and sewer main under the street, a water heater in the garage, a toilet, a kitchen sink, drain lines and the sewer line. Numbered hotspots link to services.Water mainSewer mainWater heater1Drains2Leaks and pipes3Sewer line4Toilets and fixtures5
  1. Count your fixturesShowers, tubs, dishwashers and laundry that run together.
  2. Choose the fuelNatural gas, propane or electric, based on what the home has.
  3. Set up and testGas, vent, water and condensate are connected and checked.
What we help with

Tankless water heater in Austin and the services next to it

Most tankless projects also touch one of these.

Water heater replacement in Austin

Taking out the old tank and setting the new unit.

Water heater replacement in Austin details →

Water heater repair in Austin

Fixing a tank or tankless unit that is misbehaving.

Water heater repair in Austin details →

Gas line repair

New or resized gas piping for a tankless burner.

Gas line repair details →

Water softener installation in Austin

Scale protection for the heat exchanger.

Water softener installation in Austin details →
Start here

Why Austin households look at a tankless water heater

Most people arrive here after a tank failure, a cold shower or a space problem. Which one is yours?

Your tank heater is leaking at the baseA tank that leaks from the shell is finished; tankless is one replacement path.Leaking tankThe tank is past its working years and the bills creep upA tired tank loses heat and efficiency.Aging tankThe household runs out of hot water mid-showerA bigger tank or a tankless unit are the usual answers.Running outThe heater sits in a hot attic or a cramped garageA wall unit frees floor space and can go on the exterior.SpaceYou have a tankless unit that shows an error codeScale and flow sensors are frequent causes.Error codeHot water arrives lukewarm or surges hot and coldScale, undersized unit or too many fixtures at once.Temperature swingsYou smell gas near the unit or the ventLeave and call from outside.Gas smellYou are comparing tank and tanklessOur guide sets them side by side.Compare
Why call us

Why call about a tankless water heater before you buy

The unit is the easy part. Gas sizing, venting and flow are where installs go wrong.

  • Open at any hourA heater that fails at night gets an answer at night.
  • Same-day service is availableA cold house is not scheduled out by weeks.
  • One call for water and gasThe burner, the vent and the water lines are discussed together.
  • A person to talk toDescribe your fixtures and fuel to someone, not a form.
  • Repair or swap adviceYou hear whether the old tank is worth saving.
We vs others

Tankless water heater in Austin versus staying with a tank

Neither is the winner everywhere. Here is where they differ in real use.

UsOnion Creek PlumbingvsMany other plumbing companies
Hot water supplyContinuous while there is flow capacityFlow limits apply, not tank size.A fixed tank that can run out
SpaceA wall unit with a small footprintFrees a garage corner or a closet.A floor or platform for the tank
Gas needsLarger burner, often a bigger gas lineSizing matters.A smaller burner on a standard line
Water qualityScale builds in the heat exchangerFlushing keeps it clear.Sediment settles in the tank
Local waterAustin Water’s 2025 hardness ran about 4 to 7 gpgThat is moderately hard, so scale care is part of ownership.Ignores the water entirely
Price clarityThis page explains what moves the priceAsk about pricing when you call.A figure with install surprises

Based on what is typical. Individual companies vary.

How it works

How a tankless water heater call goes

The call is a short interview about the home, then a plan.

  1. Describe the home

    Number of bathrooms, kitchen and laundry, and who uses them.

  2. Check fuel and vent

    Gas size, meter and venting path are confirmed.

  3. Pick the unit

    Capacity is matched to the fixtures that run together.

  4. Install and flush

    Connections are made and the system is purged and tested.

Pricing

What moves the price of a tankless water heater in Austin

The unit is one line. The rest depends on the house. Ask about pricing when you call.

Unit capacity

Bigger households need higher flow; capacity changes the unit.

Gas line and vent

A new run or larger pipe adds work; so does a new vent path.

Location

A wall in the garage is simple; a finished interior wall is not.

Electrical or condensate needs

Some units need a plug, a drain for condensate or both.

Water treatment

A softener or scale filter protects the unit over time.

Have this ready for the call

  • Gas or electric, and the fuel meter location
  • Number of bathrooms and big appliances
  • Where the current heater sits
  • Age of the current heater and any nameplate details

Ask about pricing when you call.

Call now, 24/7(737) 717-0737
Sizing

Sizing a tankless water heater for an Austin household

Flow, not tank size, is the number that matters

A tank is sold by its gallons. A tankless unit is sized by how many gallons per minute it can heat by a certain temperature rise. In practice you add up the fixtures that run at the same time. A shower uses a modest amount, a kitchen faucet less, and a dishwasher or washer adds more. If the sum is higher than the unit can handle, hot water thins out or turns lukewarm.

Cold incoming water also matters. In cooler months the water arriving at the house is colder, so the heater has to raise it further. A unit sized for summer can struggle in January. A good installer sizes for the cold-month case, not the average. Our overview of tankless vs tank water heaters adds more detail.

Household sizing
Household patternSizing note
One bathroom, two peopleA modest unit usually keeps up
Two bathrooms, familyPlan for two showers plus a kitchen tap
Large home with several bathsConsider two units or a high-capacity one
Tub filling, laundry and dishes togetherFlow demand is highest; size up
Rarely more than one fixture at a timeA smaller unit may do
Simultaneous use is what sizes the unit.
Matching unit to use
Placement

Garage, attic or exterior wall: where a tankless unit sits

Texas homes often hide the old tank in a garage or attic

In Texas, water heaters commonly live in garages and attics. A tankless unit is a wall-mounted box, so it can go on a garage wall, an exterior wall or inside a closet. An attic is workable but hard: it needs a safe platform, a drain pan or a drain line for any leak and adequate vent clearances. Heat in an attic can also shorten the life of electronics.

Gas-fired units need a vent that reaches the outside. Condensing units produce acidic condensate that must go to a drain. Electric tankless units have no vent, but the wiring is heavy, and the panel needs capacity. The page about water heater replacement covers the removal side of the job.

Location options
LocationGoodWatch for
Garage wallEasy access and ventingVehicle impact, freeze cover
Exterior wallDirect vent, saves interior spaceWeather exposure
ClosetHiddenNeeds clearances and air
AtticFrees living spaceAccess, heat, leak pan
Utility roomShort pipe runsNeeds venting through the roof or wall
Placement options compared.
Where it can go
Gas and venting

Gas supply and vent: what the burner needs

A tankless burner is hungry

A gas tankless heater fires a much larger flame than a tank heater when it runs. The gas line feeding it has to carry that volume, so the pipe diameter, the length of run and the meter capacity all matter. An undersized line starves the burner, causing error codes and cold spells.

Safety rules apply to the vent and the gas connection. A smell of gas is an emergency: leave first, then call from outside. For gas pipe issues, see gas line repair. If propane feeds the house, say so on the call, because the orifice and the regulator differ.

Gas and vent
  • Gas pipe diameterMust meet the unit’s stated input.
  • Distance from the meterLonger runs reduce delivered volume.
  • Vent type and pathDirect vent, concentric or power vent.
  • Condensate drainNeeded on condensing models.
  • Clearance to openingsKeep the vent away from windows and intakes.
Things the install must settle.
Water quality

Scale, descaling and the Austin Water hardness range

A heat exchanger is a narrow channel that scale can choke

Austin Water reports its 2025 water at roughly 70 to 126 ppm hardness, which converts to about 4.1 to 7.4 grains per gallon, with an average near 5.4. That is moderately hard. Which end you get can depend on your address and the plant that feeds it, so check your bill or ask your water supplier. Minerals in warm water precipitate as scale on the hottest surfaces, and a tankless heat exchanger has narrow channels with plenty of them.

The result is lower flow, temperature swings and error codes. The cure is an occasional vinegar or descaler flush through the service valves, a task many owners schedule once a year. A water softener or a scale filter takes some of the burden. The hard water guide explains the signs.

Flush steps

  1. Shut off power and gas

    Before touching any service valve.

  2. Close the water valves

    Isolate the unit with the service ports.

  3. Connect the pump and hoses

    Circulate descaler through the heat exchanger.

  4. Rinse and reopen

    Flush with clean water, check the inlet filter and restart.

A yearly flush in outline.
Decision

Tankless or a new tank: how to choose

The right answer depends on the house, not the trend

A tank heater costs less to buy and is simple to repair. A tankless unit lasts longer when maintained and takes less room, but needs better gas, venting and water care. If the old tank sits on a platform in a cramped closet and the gas pipe is already large, tankless is a straightforward swap. If the house has an electric tank and a small panel, the electrical work for an electric tankless unit may outweigh the gains.

There is also a repair decision. A tank younger than its expected life with a failed thermostat may be worth repairing, as repair versus replacement explains. A tank that leaks from the shell is finished.

Decision table
SituationLeaning
Tank leaking from the shellReplace; consider tankless
Tank in a tight spotTankless
Small gas line, no easy upgradeTank
Large household, tub useTankless with enough capacity
Rental with a short stayRepair or like-for-like tank
Frequent power loss concernsGas tank or backup plan
A starting point. The call adjusts it.
Which way to lean
Service areas

Tankless water heater service across Austin and nearby towns

Calls for tankless units from Austin and towns around Kyle go to one number.

A tankless water heater in Austin is arranged by phone. The map shows nearby towns we also cover.

Towns within about 25 milesSchematic map of towns within about 25 miles of Kyle10 mi20 mi25 miBuda, about 7 miles1Maxwell, about 7 miles2Manchaca, about 9 miles3Austin, about 10 miles4San Marcos, about 11 miles5Martindale, about 11 miles6Lockhart, about 12 miles7Dale, about 15 miles8Wimberley, about 17 miles9Bee Cave, about 18 miles10West Lake Hills, about 21 miles11Cedar Creek, about 21 miles12Kingsbury, about 22 miles13Dripping Springs, about 23 miles14New Braunfels, about 24 miles15Lakeway, about 25 miles16Canyon Lake, about 25 miles17The Hills, about 25 miles18Kyle
Schematic map. Rings show distance from Kyle; positions are approximate.
Questions

Questions about a tankless water heater in Austin

Is a tankless water heater in Austin worth it for a family home?
It can be, if the gas line, vent and flow rate match the household. It offers continuous hot water and a small footprint. Ask on the call whether your home is a clean fit.
Can a tankless unit run out of hot water?
It does not run out the way a tank does, but flow can exceed capacity. If too many fixtures run together, water turns lukewarm. Sizing for the cold months avoids this.
How hard is Austin’s water on a tankless heater?
Austin Water’s 2025 reports show a range of about 4.1 to 7.4 grains per gallon, which is moderately hard. Check your bill or ask your supplier for your address. Plan on regular flushing.
Do I need a bigger gas line?
Often, yes. A tankless burner draws far more gas than a tank. The plumber checks pipe diameter, run length and the meter before picking a unit.
What does installation cost?
The unit, the gas or electric work, venting, the drain and any water treatment all matter. Ask about pricing when you call and describe the current heater and its location.
What makes one install more expensive than another?
A new vent path, a gas line upgrade, an attic location, condensate routing or an electrical panel upgrade. A swap from a nearby tank in a garage is simpler.
Can I get a tankless heater installed the same day?
Same-day service is available for assessment and, depending on equipment, for the swap. A tank that is flooding the floor is treated as urgent.
How often should a tankless heater be flushed?
Once a year is a common routine, more often with harder water or heavy use. Ask your installer what suits the unit and your water.
My tankless unit shows an error code. What now?
Note the code, check that gas and water valves are open and that the inlet filter is clean. Persistent codes usually mean scale, flow or ignition trouble; call.
I smell gas near my water heater. What should I do?
Leave the house, keep everyone out and call from outside. Do not operate switches or lighters. Gas needs to be shut off and checked before anything else.
Can a tankless water heater go in an attic?
Yes, with a platform, a safe path to it, a drain pan or line and proper venting. Heat can age electronics, and service access is harder. A garage wall is easier.
Does a tankless heater need a softener?
Not strictly, but it benefits. A softener or scale filter slows deposits inside the heat exchanger. A yearly flush remains useful either way.
Guides

Guides on heaters and hot water

Thinking about a tankless water heater in Austin?

Call any hour. A person answers, and same-day service is available for water heaters of every type.

Call now, 24/7(737) 717-0737